The present invention relates to paperboard containers and more particularly to a paperboard container with a strong self locking bottom for carrying heavy products.
It is common practice in the art of paperboard container manufacture to provide containers with reinforced bottoms. The reinforcing may be accomplished with the addition of extra panels to the bottom or with multiple panels sequentially folded into position at the bottom when the container is formed. It is also well known to make reinforced bottoms with interlocking panels. Structures are known for such constructions which use various arrangements of slots, tongues, flaps and the like, but not all such structures have been successful.
Prior constructions have generally been complex and difficult to manufacture and assemble, requiring non-symmetrical blanks which use too much paperboard, besides being too expensive. Where attempts have been made to simplify such constructions, there has been a sacrifice of strength and durability.
Examples of prior art containers with reinforced bottoms may be found in the following prior U.S. Pat. Nos: 2,186,777 2,844,296 3,473,722 3,512,695 3,539,090 4,017,019. While many efficient self locking closures are presently known, they are usually alike in that the locking panels which are folded inside the container are generally about the same width as the slots provided for folding such panels inside. An exception is illustrated in U.S. Pat. No. 3,473,722, but in the patented container, the locking panels are not full size. In contrast to the above, all bottom panels for the container disclosed herein are full size and contribute to the formation of a four panel bottom of exceptional strength.